Cigarette inspection apparatus



Feb. 11, 1969 g, s, MEARTHUR AL 3,426,582

CIGARETTE INSPECTIONAPPARATUS Sheet Filed May 18. 1966 DOUBLE LEN THCIGARETTES SCHM TRIGGER URGE TAN TESTING ZONE SOURQE OF GAS UNDERPRESSURE C lGA RETTE w mm HN N TK R m 0mm 1w mu mmu 1 E A PD VQWW I SNNE w m IIC w m Y B ATTORNEY C. S. MCARTHUR ET AL CIGARETTE INSPECTIONAPPARATUS Feb.l1,19 69 Sheet 3 Filed May 18, 1966 INVENTOR V COLIN s.McARTHUR BY BRUCE WALL McKNlGHT qiaaa a), (5M

ATTORNEY SOURCE OF 6A5 UNDER PRESSURE Feb. 11, 1969 c. s. M ARTHUR ET AL3,425,582

CIGARETTE INSPECTION APPARATUS Filed May 18, 1966 Sheet of 4 a ki 22 E2045 2 5 5 I It. 5

INVEN'T'DR COLlN S, McARTHUR BY BRUCE WALL McKN\GHT ATTQRNEY c. s. MARTHUR ETA L 3,426,582 CIGARETTE INSPECTION APPARATUS Feb. 11, 1969Filed May 13, 1966 Sheet 4 or;

TRANSDUCER MEANS U DER PRE SSLRE SOURCE OF GAS UNDER PRESSURE Facyll.

THROTTLE INVENTQRS COLIN s. McARTHuR BRUCE WALL McKNIGHT 07 g M/LATTORNEY United States Patent 12 Claims ABSTRACT OF THE DISCLOSUREInspection apparatus for filter cigarettes, in which the interior of thecigarette is subjected to a pressure differing from the externalatmospheric pressure, and the internal pressure is utilized to control abistable fluid amplifier, which in turn actuates an ejecting mechanismif the internal pressure in the cigarette indicates that the cover ofthe cigarette is leaky. The inspection and ejection of faulty cigarettestakes place at a single station on the periphery of a rotating drum. Theperipheral length of that station on the drum surface is substantiallyequal to the spacing between cigarettes on the drum. The pressure isapplied to the cigarette throughout the length of its passage throughthe station. Synchronizing means is provided so that the ejectionapparatus operates only during the latter part of the passage of acigarette through the station, thereby ensuring that the pressurecondition in the cigarette is stabilized before the ejection apparatusis actuated, and also ensuring that only the cigarette under test isejected if an indication of a leak is found.

This invention relates to the inspection of cigarettes, and moreparticularly relates to the inspection of cigarettes for imperfectionscausing air leaks therein.

Sherrill Patent No. 2,951,364 shows an apparatus for inspectingcigarettes for air leaks by passing a flow of air through eachcigarette. A mechanical sensing device incorporating a movable memberresponds to an abnormal air flow, thereby indicating a leak in theparticular cigarette under inspection. In response to movement of themovable member, an ejector mechanism is actuated to eject the defectivecigarette. Although mechanical sensing arrangements for detectingabnormal air flow conditions have been suitabe in the past, they areslow as compared to the speeds available in present cigarette-makingmachines and the even greater speeds expected in future machines. It istherefore desirable to have an inspection arrangement for leak detectionthat can handle cigarettes at the fast rate at which they may now beproduced.

It is an object of the present invention to provide an apparatus for theimproved inspection of cigarettes for leaks.

Another object of the present invention is to provide for the high speedinspection of cigarettes for leaks.

Another object of the invention is to provide an apparatus for theinspection of cigarettes for leaks employing fluid principles to achievehigh speed response of a rejection mechanism to an inspection mechanism.

These and other objects and advantages of the invention will be moreapparent as the detailed description of one presently preferred butmerely illustrative embodiment of the invention proceeds, with referenceto the drawings, in which:

FIG. 1 illustrates an inspection apparatus embodying the invention,having mechanical parts shown in a simplified perspective view and fluidamplifier means parts shown in a simplified diagrammatic vie-w;

FIG. 2 is an end view of a cigarette-conveying apparatus incorporatingone form of means for subjecting the cigarettes to a source of gas forinspection for leaks and one form of cigarette rejection means;

FIG. 3 is a side view of the apparatus of FIG. 2;

FIGS. 4, 5, 6, and 7 are sectional views of portions of the apparatusshown in FIG. 3, taken along the section lines 4-4, 55, 6-6, and 7-7 ofFIG. 3 and looking in the directions of the corresponding arrows in thatfigure;

FIG. 8 is a side view of a cigarette-conveying apparatus such as shownin FIG. 3 incorporating a second form of cigarette rejection meansresponsive to the fluid amplifier means;

FIG. 9 is a sectional view of a portion of the apparatus shown in FIG.8, taken along section line 9-9 of FIG. 8 and looking in the directionof the arrows;

FIG. 10 is a partial detail view showing a variation on the second formof rejection means; and

FIG. 11 is a simplified view of a second form of means for subjectingthe cigarettes to a source of gas for inspection.

As employed herein, the term cigarette is a generic term inclusive of afilter cigarette or a non-filter cigarette, as well as a single lengthor multiple length cigarette. The term is also intended to include anyself-contained smoking article, such as a cigar, which may be tested inaccordance with the invention.

Briefly, the present invention provides a leak inspection system whereingas at an elevated or reduced pressure is applied to each of asuccession of cigarettes, and the change in pressure attributable toleaks in the cigarette controls fluid amplifier means so as to divertthe output of said means from a first outlet to a second outlet, saidsecond outlet being arranged to actuate means for ejecting the leakycigarette in question.

The apparatus according to the invention provides very fast responsebetween testing and ejection. This is important because with present daycigarette-making machines approximately 1000 dual cigarettes per minute,or 17 dual cigarettes per second, are handled. This means that thetesting and ejection mechanism has to be extremely rapid, e.g. it musttest about 17 dual cigarettes per second and reject the leaky ones.Because of this rapid cigarette handling rate, the apparatus must alsobe extremely reliable, because in even a momentary mechanical break-downa rapid build-up of untested cigarettes or cigarettes which have beenincorrectly rejected would occur. The apparatus according to theinvention meets the felt need, because, operating upon fluid principles,it is extremely rapid in response and it is extremely reliable, bothprincipally because there is no inertia involved except that of thefluid, which being a gas typically, is extremely low in mass andaccordingly in inertia.

Referring to FIG. 1, a conveyor such as a drum assembly 20 is showncarrying a plurality of double length cigarettes 22 thereon, each ofwhich is to be inspected for leaks. Each dual cigarette typicallycomprises tobaccofilled portions 22a and 22b at the ends thereofseparated by a double length filter section 22c in the middle thereofand fastened together by means of tipping paper and adhesive.Subsequently, each double length cigarette is cut in the middle offilter section 22c to produce two standard filter-type cigarettes. Thecigarettes are applied to, carried by, and removed from the drumassembly 20 by means presently to be described. The drum assembly 20 isrepresented only diagrammatically in FIG. 1; it is shown in more detailin the other figures.

The drum assembly rotates as shown by arrow 24. As each cigarettecarried on the drum assembly passes through a testing zone 26, gas(typically air) under constant pressure greater than ambient pressure isapplied to the cigarette from a conduit 28. It is possible, but notpreferred, to use a constant vacuum system instead of an elevatedpressure system. With a vacuum the leak pressure-pulse ispositive-going, but with an elevated pressure (as illustrated) it isnegative-going. In one form of the invention, the conduit 28 isconnected to a source of gas under pressure (not shown) through aregulator 30 and a surge tank 32 to maintain the flow of gas constant. Aslip ring arrangement described in detail in connection with FIGS. 2 and3 couples the conduit 28 to each cigarette as it passes through thetesting zone 26.

Gas flows through the cigarette in the testing zone and out of thecigarette and into an outlet conduit 34 connected to a filter 36. Thefilter filters out any tobacco that may be present in the gas. The gasis then led, by a conduit 38, to fluid amplifier means shown in thelower half of FIG. 1 within the broken line envelope 46. Means 46operates on fluid amplifier principles, that is to say, the fluid inputfrom conduit 38 controls the fluid output from means 46, so that theoutput is diverted to a first destination or a second destination,depending upon the level of fluid input pressure at conduit 38. One ofthe two destinations controls the rejection means for the cigarettes,and the other destination is an exhaust.

The fluid amplifier means 46 comprises a Schmitt trigger 47 responsiveto the input of conduit 38 and controlling a pair of NOR gates 50, '54,which in turn control a control flip flop 58. An output flip flop 61having a greater output than control flip flop 58, is controlledthereby, and either exhausts its output or applies it to conduit 62which is connected to cigarette rejection means associated with theinspection drum. Fluid power is supplied to fluid arnplifier means 46from power source conduit P, and in the illustrated embodiment 12.5p.s.i.g. gas pressure is applied at conduit P.

The Schmitt trigger 47 is a known all-fluid amplifier circuit having thecharacteristic that the output thereof is switched from its normaloutput port to the other output port in response to, and for theduration of,

change in a monitored input pressure exceeding a predetermined level. Inthe circuit of fluid amplifier means 46, Schmitt trigger 47 accordinglyacts as a detector which produces a pulse in one of the output ports inresponse to a pressure signal at conduit 38 exceeding said predeterminedlevel. Schmitt trigger 47 is powered from power source conduit P by aconduit 47a supplying the full 12.5 p.s.i.g. together with a conduit 47bhaving a fixed restrictor 48 to apply a lower pressure, and a conduit47c having a variable restrictor 49 to apply a lower variable pressureadapted to set the aforesaid predetermined level.

The output port conduits 47d, 47e of Schmitt trigger 47 are appliedrespectively to NOR gates 50, 54. A second control input is applied toNOR gates 50, 54 by a timing pulse conduit circuit '55, which conduit isconnected to power source conduit P through variable restrictor 56 so asto supply an input signal at branches 55a, 55b to NOR gates 50, 54respectively. Conduit 55 includes a side branch 550 which is open ended.An apertured disc assembly 57 is arranged to alternately block andunblock side branch 55c. Apertured disc assembly 57 includes a shaft 57acarrying a disc 57b having a plurality of peripherally located apertures57c spaced circumferentially on a constant radius. Side branch 55c abutsthe circumference traced out by the apertures 57c during rotation ofdisc 57b with shaft 57a.

As disc 57b is rotated thereby bringing the plurality of apertures 57csuccessively into coincidence with the open end of side branch 550, thepressure in conduit 55 is repeatedly allowed to exhaust each time anaperture 57c comes into such coincidence. The arrangement is such thatthe period between adjacent apertures 57c exactly equals the periodbetween consecutive cigarettes 22 reaching the midpoint of testing zone26. To accomplish this, shaft 57a may actually be the same shaft uponwhich the inspection drum is mounted, as is illustrated in FIG. 1.

Alternatively shaft 57a can be separate from but driven in exactsynchronization with the inspection drum and its shaft, e.g. by gearing.In either case the number of apertures 57c will equal the number ofcigarette positions on the inspection drum. It is also possible toemploy fewer or more apertures, spaced at greater or lesser angularamounts, provided that the shaft on which disc 57b is mounted is drivenat the correct proportion of the speed of the inspecion drum shaft tokeep the period between apertures 57c equal to the period betweencigarettes 22. In any event, branch 55c is positioned angularly so thatthe rotation of disc 57b causes a series of negative-going pressurepulses, dropping to zero, corresponding to the coincidence of successiveapertures 57c with branch 550, which pulses provide an input at conduitbranches 55a 55b to NOR gates 50, 54 synchronized with the arrival ofthe respectively associated cigarettes 22 at the mid-point of thetesting zone. Power is applied to NOR gates 50, 54 from conduit 53 whichis connected to power source conduit P.

NOR gates are fluid amplifier devices that attain one state when neitherof the two input ports receive a pressure signal, and attain anotherstate when either or both input ports do receive a pressure signal. Withrespect to NOR gates 50, 54 this means that when a pressure signal isreceived at either or both of input conduits 47d, 55a of NOR gate 50,the output of that NOR gate will be directed to exhaust port 50a.Similarly, when either or both of input conduits 47c, 55b carries afluid pressure signal to NOR gate 54, the output of that NOR gate willbe directed to exhaust port 54a. On the other hand, when there is nosignal on input conduits 47d, 5512, then NOR gate 50 will direct itsoutput to output conduit 50b which forms a first input for control flipflop 58. When no signal appears at input conduits 47e, 551),NOR gate 54will direct its output to conduit 54b which forms a second input forflip flop '58.

A flip flop is a fluid amplifier device which is bistable, i.e. has anoutput flow which exists substantially totally in either of two outputchannels, until positively switched to the other channel by anappropriate input signal. A common example of a fluid amplifier flipflop is the usual bistable fluid amplifier wherein the output flowadheres to the wall of a chamber leading to one output channel until aproperly directed input pressure signal snaps it off that wall andacross the chamber to lock onto an opposite wall leading to the otheroutput channel.

Flip flops 58, 61 derive their power stream from power source conduit Pby conduits 58a, 61a respectively. Conduit 58a is provided with a fixedrestrictor 59 to provide a reduced pressure power stream therefor, sothat flip flop 61 has a correspondingly greater power output than flipflop 58. The output stream of flip flop 58- is switched into outputconduit 58b when the pressure at input conduit 54b exceeds that at inputconduit 50b by a predetermined amount. Conversely, the output stream offlip flop 58 is switched into output conduit 580 when the pressure atinput conduit 50b exceeds that at input conduit 54b by a predeterminedamount. The output stream from flip flop 61 is switched into exhaustport 61b when the input pressure from conduit 58b exceeds the inputpressure from conduit 580 by a predetermined amount. Conversely, theoutput stream of flip flop 61 is switched into output conduit 62 whenthe input pressure from conduit 58c exceeds the input pressure fromconduit 58b by a predetermined amount. As aforesaid, the output conduit62 leads to the inspection drum where it is connected to the ejectionmechanism, so that when an output appears in conduit 62 the leakycigarette will be ejected.

Viewed at its terminals therefore, fluid amplifier means 46 has a powerstream introduced from power conduit P, and this power stream iscontrolled by the pressure signals arriving at input conduit 38 fromcigarettes under test. The testing of a leaky or an acceptable cigarettewill be represented by the pressure in input conduit 38 and will,

respectively, cause bistable switching of the power stream derived frompower source conduit P into conduit 62 to eject that cigarette, or intoexhaust to leave that cigarette as 1s.

The specific means shown in FIG. 1 as an example of fluid amplifiermeans 46- ac'hieves the aforesaid bistable fluid amplifier terminalcharacteristics by cooperation of the various circuit elements withinfluid amplifier means 46-, as follows. Schmitt trigger 47 discriminatesbetween input pressure signals at conduit 38 which do not meet theaforesaid predetermined level, and those that do. The output of Schmitttrigger 47 is directed to conduit 47d at all times when the signal atinput conduit 38 does not meet the aforesaid predetermined level. Assoon as the signal at conduit 3 8 meets the aforesaid predeterminedlevel, the output of Schmitt trigger 47 is switched in response theretofrom conduit 47d to conduit 47e. By adjustmentof variable restrictor 49,the point at which this switching takes place can be adjusted, i.e. theaforesaid predetermined level can be set. It may be desirable to set theaforesaid predetermined level at any of a range of values depending uponwhat quality standards as re gards leaky cigarettes the user of theapparatus desires to erect.

The signal at conduit 38 is of course inversely proportional to the leakrate of the cigarette 22 in question, i.e. a higher leak rate at thecigarette 22 produces a lower pressure at conduit 38-. The input signalwhich causes Schmitt trigger 47 to switch from conduit 47d to 472 istherefore a negative-going pressure Waveform. On the other hand, thesignal produced at conduit 47d by Schmitt trigger 47, and switched asaforesaid to channel 47a, is a positive-going pressure signal. Thatsignal is switched to conduit 472 only so long as the input signal whichcaused the switch appears at conduit 38. The output of Schmitt trigger47 returns to conduit 47d as soon as that input signal returns above theaforesaid predetermined level, so that conduit 47c receives a pulse ofoutput from Schmitt trigger 47 in response to and for the duration oftime that the input signal at conduit 3-8 meets the aforesaidpredetermined level. In effect, this means that as long as the leakycigarette is under test, the Schmitt trigger 47 will direct its outputinto conduit 47e.

For purposes of the following discussion, reference to the existence ofa signal at either of conduits 47d or 472 means that the positivepressure output of Schmitt trigger 47 is present in that particularconduit, and reference to no signal being in either of these outputconduits means that the output of Schmitt trigger 47 is present in theother one of these output conduits. Reference to no signal being atconduit branches 55w or 55b means that branch conduit 550 has alignedwith one of apertures 57c so that the pressure in conduit 55 has droppedto zero. Conversely, reference to a signal being at either of conduits55a or 55b means that branch conduit 550 does not coincide with anaperture 570 and the pressure in conduit 55 is at an elevated value.Hereinafter when no signal is impressed at each of the input conduits toa NOR gate, that will be referred to as no signal-no signal. Similarly,when a signal is applied to one input conduit to a NOR gate and nosignal is applied to the other input conduit, that will be referred toas signal-no signal. Finally when a signal is applied to each inputconduit of a NOR gate, that will be referred to as signal-signal.

NOR gate 50 constitutes the rejection NOR gate, in that when conduit 50bis energized with the output thereof it triggers the rejection of theleaky cigarette, by changing the state of the flip flops 58, 61 to theirrejection state, as will be explained presently. NOR gate 54 constitutesthe restoring NOR gate, in that when conduit 54b is energized with theoutput thereof it restores flip flops 58, 61 to their non-rejectionstate.

In accordance with the aforesaid rules, a leaky cigarette produces aswitch of the output of Schmitt trigger 47 from conduit 47d to conduit47c, thereby producing a no signalno signal condition at NOR gate 50,and a signal-no signal condition at NOR gate 54. This means that NORgate 50 must flip to or remain at the output state wherein the rejectionoutput conduit 50b receives the output stream, and the NOR gate 54 mustflip to or remain at the condition wherein the exhaust port 54a receivesthe output stream. Thus conduit 50b is energized and conduit 54b isde-energized, causing the power stream of flip flop 58 to switch intooutput conduit 580 from output conduit 58]), or to remain at outputconduit 580 if it is already there. Flip flop 58, having fluid pressurein output conduit 58c, and an absence of fluid pressure in outputconduit 58b, causes flip flop 61 to switch the power stream thereof fromexhaust port 61b to the output conduit 62, or to remain at outputconduit 62, as the case may be.

Thus the overall rejection sequence in response to a leaky cigarette isthat a negative-going pulse at input conduit 38, meeting the aforesaidpredetermined level, causes an output flow in conduit 62 which isemployed as hereinafter described to reject the very cigarette whichcaused that flow. It will be remembered that the fluid flow in outputconduit 62 is commenced only when the synchronization assembly 57produces a. pulse indicating that the center of the testing are 26 ofthe cigarette 22 in question has been reached. It is thus guaranteedthat the correct cigarette is ejected in response to the testingmeasurement. As will be explained hereinbelow, the output flow inconduit 62 persists, due to the bistable nature of flip-flops 58, 61until the center of the testing zone 26 is reached by the nextconsecutive cigarette 22, i.e. until the next consecutive aperture 570coincides with branch conduit 550. At that latter event, the flow inoutput conduit 62 is either continued (rejecting the new cigarette) orswitched into exhaust port 6111 (accepting the new cigarette) dependingupon the new input signal at input conduit 38. The output flow inresponse to any single test is therefore in the form of a pulse whoseperiod is determined by the incidence of successive apertures 57c atbranch conduit 55c, i.e. by the period of traverse from the testcigarette being at the mid-point of testing zone 26 to the nextsuccessive cigarette being at that mid-point. The pulse period will bemultiple if successive cigarettes are leaky, as will appear hereinafter.

The resetting of flip flops 58, 61 so that the power stream of flip flop61 is switched from output conduit 62 to exhaust port 61b, results whenan acceptable cigarette follows a leaky cigarette, as just mentioned.This occurs as follows. As the inspection drum turns so that the nextcigarette 22 is brought into the testing zone 26, the apertured disc 57bwill also turn so that the open end of branch conduit 550 will move fromone aperture 570 to the next. While between apertures, the branchconduit 55c is closed off by disc 57!), so that the pressure in conduit55 is elevated to yield a signal at conduit branches 55a, 55b to NORgates 50, 54. The presence of a signal during that interval at each ofNOR gates 50, 54 means that each of the NOR gates switches its outputflow to its exhaust port. Since flip flops 58, 61 remain locked in theirstate until positively restored, this action does not affect therejection state of flip flop 61. However when the next aperture 570coincides with the open end of branch conduit 55c, no signal is againimposed on each of NOR gates 50, 54 at the branch conduits 55a, 551)respectively. Assuming that the cigarette: corresponding to this nextaperture is not leaky, no signal will appear in conduit 47c applied toNOR gate 54, but the normal signal output of Schmitt trigger 47 willappear in conduit 47a to NOR gate 50. The signal-no signal condition onNOR gate 50 will flip the output thereof from the output conduit 50 h tothe exhaust port 50a. The no signal-no signal condition on NOR gate 54will flip the output thereof from exhaust port 54:! to output conduit:54b. The presence of fluid pressure in conduit 54b and the absencethereof in conduit 50]; switches the output of flip flop 58 from conduit580 to conduit 58b. This in turn switches the output of flip flop 61from rejection output conduit 62 to the exhaust port 61b. The acceptablecigarette following a leaky cigarette thus itself causes the resettingof flip flops 58, 61 so that the rejection flow pulse in conduit 62ceases, and that cigarette is not rejected.

After the flip flops have been restored to the condition just describedwherein there is no output in rejection conduit 62, rejection can bepracticed again at the next aperture 57c if the output signal fromSchrnitt trigger 47 is switched from its normal output conduit 47d tooutput conduit 472, as has already been explained. If two or more leakycigarettes appear consecutively under test, the repeated presence of asignal from Schrnitt trigger 47 to output conduit 478 will mean arepeated no signal-no signal condition on NOR gate 58, and a repeatedsignal-no signal condition at NOR gate 54. The rejection state of flipflops 58, 61 is thus continued for the second consecutive leakycigarette. Similarly, if two or more acceptable cigarettes occur in arow the normal output of Schrnitt trigger 47 into conduit 47d willpersist, thus repeating a signal-no signal condition at NOR gate 50 anda no signalno signal condition at NOR gate 54. This means that theoutput of NOR gate 50 will remain at its exhaust port 58a, and theoutput of NOR gate 54 will remain at its restoring output conduit 54!).The flip flops S8, 61 accordingly will not change from their statewherein the output of flip flop 61 is directed to exhaust port 61b.

The various fluid switching actions just described at the componentswithin fluid amplifier means 46 occur very rapidly, and without theintervention of mechanical moving parts with the exception of disc 57bwhich may be positively connected to or geared to the inspection drumand is accordingly virtually foolproof. While disc 57b is mechanical,that detracts in no way from the totally fluid principles of the fluidamplifier means 46. This is because the disc 57]; rotates faster orslower together with the inspection drum. It introduces no inertiaconsiderations. The disc 57b is merely a fluid pulse generator whosefrequency is controlled by the inspection drum, and need not bemechanical at all. No mechanical element must respond to the fluidpressure signal, i.e. no mechanical element is in the chain of elementsresponding to the input signal. The system is easily capable of testingand producing a rejection signal or not at the aforesaid 17 dual lengthcigarettes per second rate,

and moreover is so reliable that production stoppages because ofbreak-downs is virtually non-existent. This is an important advance inan art wherein a number of cigarette-making machines may all be operatedat the same time each producing 17 dual length cigarettes per second, ormore.

FIGS. 2-7 show in greater detail the construction of a first form of thedrum assembly 20 shown in diagrammatic form in FIG. 1. This first formemploys valves to eject the rejected cigarettes by the valving on ofpositive air pressure, the values being turned to the on condition by apressure switch operated by output conduit 62. In FIG. 2, the drumassembly 20 is adapted to receive a series of cigarettes from a drumassembly 70. The drum assembly 20 rotates clockwise, as shown by arrow24, while the drum assembly 70 rotates counterclockwise, as shown byarrow 72. The surfaces of the drum assemblies pass tangentially adjacentto each other at a cigarette transfer zone 74, and cigarettes aretransferred from the drum assembly 70 to the drum assembly 20, asdescribed in greater detail below. The cigarettes transferred to thedrum assembly 20 are thereafter tested as they pass through the testingzone 26 and are either rejected as being defective or are retained onthe drum. Those cigarettes retained on the drum are thereaftertransferred to a further drum assembly 76 which rotates counterclockwiseas shown by arrow 78. Cigarettes are transferred to the drum assembly 76in transfer zone 80, as described below.

As shown in FIG. 3, the drum assembly 20 comprises a fixed head 82 whichserves to mount the drum assembly to a frame (not shown). Journalledwithin the head 82 is a rotatable drum 84 which extends at one endthrough the fixed head 82 as a reduced diameter portion 84a. The drum 84also includes an intermediate stepped portion 841) and an end flange840. Another fixed head 86 abuts the end flange 840.

The drum 84 carries a plurality of rows of cradles 88 thereon, the rowsbeing arranged around the circumference of the drum upon its outersurface. Each cradle 88 is advantageously concave and semicylindrical soas to cradle a portion of the cylindrical surface of one of thecigarettes 22 carried on the drum. The central pair of cradles 88a ineach row receive the cylindrical surface of substantially the entirefilter portion 22c of the double length cigarette in the row.

Each cradle 88 has a central orifice 90 opening underneath the cigarettein the cradle. Each of the central elongated cradles 88a has a pair ofsuch orifices. Orifices 90a are also included in the drum 84 in each rowof orifices 9']. Internal passageways (not shown) within the drum 84selectively connect (by appropriate valve action) the orifices 90a to apositive source of gas (typically air) pressure and the orifices 90 to asource of vacuum. Thus each cigarette 22 on the surface of the drum 84is either ejected from the cradles 88 by positive gas pressure appliedto the orifices 90a or retained on the cradles by vacuum applied toorifices 90.

In this regard, the surfaces of the drum assemblies 78 and 76 aresimilarly formed with cradles and orifices to retain the cigarettes onor eject the cigarettes from the cradles. In the system of FIG. 2, aseach cigarette on the drum 70 enters into the transfer zone 74, it issubjected to a positive gas pressure ejecting that cigarette from thecradles on that drum onto the cradles of the drum 84. At the same time,the orifices 90 in the cradles 88 on the drum 84 within the transferzone 74 are subjected to a vacuum to receive the cigarette from the drum70 and to retain the transferred cigarette on the surface of the drum84. In like fashion, orifices 90a on the drum 84 when in the transferzone 88 are subjected to positive gas pressure and the orifices in thecradles on the drum 76 are subjected to vacuum to transfer cigarettesfrom the drum 84 to the drum 76- As shown in FIGS. 3 and 4, theintermediate stepped portion 84b of the drum 84 includes a plurality ofholders 92. Each holder is mounted within a corresponding passage 93 andmay be reciprocated in the directions indicated by arrow 94 (FIG. 4) bya driving mechanism (not shown) in the drum 84. When a cigarette istransferred from the drum 70 to the drum 84 as described above, theholder 92 on the drum 84 positioned in the transfer zone 74 is in aretracted position within the drum portion 84b. After the cigarette istransferred to the drum 84, the holder 92 is moved outwardly to theposition shown in FIGS. 3 and 4 to engage one end of the cigarette 22transferred to the drum 84. In so engaging the cigarette end, thecigarette is moved slightly to the right with respect to FIG. 3 so thatthe other end thereof is firmly engaged by surface 96 of the drum flange840 (FIG. 5).

As shown in FIGS. 3 and 4, each cigarette holder 92 includes a passage92a therein that communicates with a passage 98 in the drum portion841:. Similarly, each contact area of the drum flange 840 (FIG. 5)engaging an end of a cigarette communicates with a passage 99 in thedrum flange. It will be noted, then, that the passages 98 and 92acommunicate with one end of the cigarette, and the passage 99communicates with the other end of the cigarette. These passages areprovided for subjecting the cigarette to a flow of gas for leak testingas described immediately below.

Gas input conduit 28 is shown in FIG. 3 as mounted on the fixed head 82.FIG. 4 shows that conduit 28 communicates with a passage 100 within thefixed head 82. The passage 100 terminates in a portion 100a that isshown in FIG. 7 as subtending an angle of roughly 25 of rotation of thedrum 84. The angular extent of the passage 100a defines the extent ofthe cigarette testing zone 26. At the other end of the drum 84, as shownat the righthand side of FIG. 3, the gas outlet conduit 34 is connectedto the fixed head 86. As shown in FIG. 5, the outlet conduit 34communicates with a passage 102 in the fixed head. As will be noted fromFIG. 6, the passage 102 subtends the same angle as the passage 100a andis located directly opposite the passage 100a.

The passages 100a and 102 in the fixed heads 82 and 86 are positioned soas to communicate with the passages 98 and 99 in the drum portions 84band 840. Hence, during the portion of the revolution of the drum 84 inwhich the passage 98 leading to a particular cigarette holder 92communicates with the passage 100a, gas under pressure is provided viathe passages 28 and 98 to that cigarette. The gas flows through thecigarette and into the associated passage 99 in the flange 840 at theother end of the drum, and flows out of that passage into the passage102 and thence into the outlet conduit 34 to the filter 36 and fluidamplifier means 46 shown in FIG. 1.

Thus as each cigarette passes through the testing zone 26, it issubjected to a flow of gas therethrough. If the cigarettes are all ofuniform draft, both the flow of gas and the pressure thereof will beconstant. However, if any one of the cigarettes has a leak therein, thegas. flow will leak out, thereby producing the aforesaid negativegoingpressure signal for the duration of testing of that cigarette. Inaccordance with the presently discussed form of rejection means, theresultant flow in output conduit 62 will actuate relay 68 (FIG. 3),ejecting the leaky cigarette.

With respect to FIG. 2, the angular extent of the testing zone 26 ispreferably slightly less than the angular separation of adjacent rows ofcradles 88 on the drum 84, so that after each cigarette passes out ofthe testing zone, there is a short period of time before the nextcigarette enters the testing zone. Also, the synchronization pulse fromconduit 55 (FIG. 1) occurs at the mid-point of testing zone 26, so thatthe arm (FIG. 2) is preferably located at the extreme latter end of themovement of the cigarette within the testing zone 26, as illustrated.There is thus provided one-half the zone 26 for the relay 68 to react toeject the leaky cigarette. This is fully ample, even at the contemplatedultra-high cigarette rate, and the mechanical nature of the relay andits switch does not comprise that rate significantly. The angular extentof the testing zone 26 may alternatively be the same as or slightlygreater than the angular separation of adjacent rows of cradles 88 onthe drum 84. However, the angular extent of the testing zone 26 shouldnot exceed one and one-half times the angular separation of adjacentrows of cradles 88, if the synchronization pulse is to occur one-halfthe aforesaid angular separation before the position of arm 104.

Referring to FIG. 3, the relay 68 is carried within a housing in arm104. The relay controls a plunger 68a which, when the relay isenergized, may actuate that one of a plurality of valve operators 106which happens to be passing plunger 68w on the rotating drum portion84a. The valve operators 106 control the application of vacuum to theorifices 90 and pressure to the orifices 90a so as to cause thecigarettes in the cradles to be retained upon the drum or to be ejectedtherefrom. Each of the valve operators 106 is associated with acorresponding one of the rows of cradles 88, and is rotatable on its ownlongitudinal axis. Each valve operator includes a spindle 108 to whichare attached a pair of radial fingers 110 and 112.

The relay housing of arm 104 is so positioned and the relay plunger 68ahas an axial movement of suflicient length so as to intercept any finger112 passing by when the plunger 68a is in its extended position, butadapted to clear any finger 112 passing by when the plunger is in aretracted position. The setting of the valve operators 106 isundisturbed as the drum 84 rotates until an electrical signal to therelay 68 causes the plunger to be extended, as shown in FIG. 3, so as tointercept the finger 112 then in proximity to or next coming intoproximity to the plunger 68a, thereby to rotate 90 the valve operator106. The valving action of the valve operator 106 is such that the 90turn thereof acts to switch the orifices 90 associated therewith from anormal gas vacuum condition and to apply a positive gas pressure to theassociated orifices 90a. This action tends to eject the associatedcigarette from the cradles 88.

It will be noted from FIG. 7 that the relay plunger 68a is positioned atthe bottom region of the testing zone 26. Hence each cigarette tested inthe zone and detected as leaking, thereby causing the relay 68 to beactuated, is ejected from the surface of the drum 84 with gravityassisting air pressure. It should be noted in this connection that eachof the cigarette holders 92 is moved to its retracted position after thecigarette has passed through the testing zone 26 so that the associatedcigarette may be ejected following the test or may, if found acceptable,be transferred to the drum 76 as explained below.

Referring again to FIG. 2, a finger 120 is fixed to the head 82. Thefinger is adapted to intercept the finger 110 on any valve operator 106that is not in the vacuum posi tion. Hence each of the valve operatorswhich has been actuated by the relay plunger 68a to eject its associatedcigarette is moved to the vacuum position for proper operation in thenext cycle of operation when a cigarette is again received from the drum70 for testing.

Those cigarettes passing through the testing zone 26 and not ejectedfrom the surface of the drum 84 continue to be retained on the drumuntil they reach the transfer zone (FIG. 2). In the transfer zone 80,the vacuum supplied to the orifices in the cradles 8 8 is temporarilyremoved by means of a valving arrangement (not shown) so that thecigarettes may be transferred to the drum 76.

When the form of apparatus including arm 104 and relay 68 is employed,the aforesaid output pulse of air in output conduit 62 is advantageouslyemployed (FIG. 3) to actuate relay 68 to eject the leaky cigarette. Inone form, a pneumatic switch 105, preferably of the diaphragm type, isdirectly actuated (not shown) by the pressure pulse from conduit 62 andthereby closes electrical contacts for the duration of that pulse,connecting electrical power leads 105a to relay 68. In general, fluidback-up pressure is not a problem with the output flip flop 61 of means46, because the alternative output is exhaust 61b. Therefore, conduit 62can be connected directly to switch 105. To avoid back-up however, or toemploy a higher pressure rated switch 105, which may have betteroperating characteristics, a pneumatic relay 107 may be employed toreceive the pulse from conduit 62 and supply a separate, and stronger,pulse to switch 105 via conduit 107a, as illustrated. Pneumatic relay107 may be a diaphragm operated needle valve, the diaphragm of whichresponds to the pressure in conduit 62, and the power circuit of whichruns from a pneumatic supply conduit 107b to conduit 107a. The pressureat 107b can be whatever is necessary and suitable. As anotheralternative (not shown), the pneumatic pressure of pneumatic relay 107can actuate member 68a via a pneumatic cylinder (not shown) rather thanby electrical means, although this is not preferred. Although thesevarious approaches each introduce electrical and mechanical inertia intothe rejection system, the improvement contributed by use of fluidamplifier means 46 in detection and pulse generation is so superior thatthis can be tolerated, especially in adapting pre-existing machineshaving a relay 68 and valve operators 106 to the present invention.Moreover, the amplification of the leak pulse by means 46 allows fasterand more rugged mechanical or electrical rejection means to be employed.

However, the system also can operate with a totally fluid rejectionmeans, thus introducing no mechanical or electrical inertia anywhere, bypracticing the alternative form shown in FIGS. 8l0. In that form, thearm 104, relay 68, and valve operators 106 are omitted. The positivepressure orifices 90a are retained, but they are no longer controlled byvalve operator 106. Instead, a passage 103 (FIG. 9) appears in fixedhead 86, and each row of positive pressure orifices 90a is fed positivepressure by a passage 91, one of which is shown in FIG. 8. Each suchpassage 91 is located circumferentially midway between the row oforifices 90a to which it is connected and the row immediately in advancethereof on drum 20, i.e., in the direction of rotation of drum. 20. Eachpassage 91 terminates at an open end 91a abutting, and normally closedby, fixed head 86. Ends 91a are on a common radius with passage 103 infixed head 86. Passage 103 commences at the circumferential terminalpoint of passage 102, and continues for about the angular space betweenadjacent cigarettes 22. Because each passage 91 is one-half thatdistance in advance of its orifices 90a, the sequencing is such thatpositive pressure, if applied, commences at the mid-point of testing.

Since ends 91a are normally abutted with head 86, no pressure normallyemanates therefrom. But when a passage 91 moves with drum until its end910 communicates with passage 103, any positive pressure introduced intopassage 103 from output conduit 62 will emanate from the line oforifices 90a associated with that particular passage 91. The positivepressure force exerted on the cigarette 22 at orifices 90a can be equalto, greater than, or less than, the vacuum force exerted thereon atorifices 90. If it is greater than the vacuum force, clearly a thecigarette will be ejected. But it will be remembered that there iscentrifugal force on each cigarette, and that there is effective gravityforce at the bottom portion of drum 20. Consequently in practice apostive pressure force equal to or even somewhat less than, the vacuumforce, can also cause ejection of that cigarette. Where a high vacuum isemployed, a pressure booster can be employed on conduit 62 to overcomesame. This is shown in FIG. 10 where the pneumatic relay 107 already described with reference to FIG. 3 is shown supplying higher pressure topassage 103 in response to a pulse on conduit 62. The positive pressurepulse, from conduit 62 directly or from conduit 107a, can alternativelybe applied (not shown) directly to vacuum orifices 90 to negate orsubstantially negate the vacuum force thereat, rather than being appliedto separate orifices 90a as shown.

Relay 107 may be a valve, as mentioned above, and may be actuated by asuitable pressure sensitive transducer means 108, as shown. Transducermeans 108 may be a pressure sensitive switch.

As described above, the system of FIGS. 1-10 provides for a flow of gasthrough each cigarette. The fluid amplifier means 46 monitors the outletline, and hence requires a filter to remove tobacco from the gas. It maybe desirable, however, not to sense dirty gas that has passed through acigarette, and the alternative embodiments of FIG. 11 are intended to oerate by sensing clean gas prior to its application to the cigaretteunder test.

Referring to FIG. 11, gas under constant pressure is applied to abranched conduit 122. The common leg 124 of the conduit is connected toinput conduit 38 which leads to fluid amplifier 46, while legs 126 and128 are coupled to opposite ends of cigarette 22. Depending upon theimperiousness of the cigarette paper to the flow of gas theret-hrough,little or no pressure drop occurs at the comman conduit leg 124 unlessthere is a leak in the cigarette. When there is a leak however, thenegative-going pressure pulse is reflected at the input to thecigarettes at conduit 124, and accordingly is monitored by input conduit38 to operate means 46 in the same manner as has already been described.The chief difference is that with the arrangement of FIG. 11, which maybe practiced with any of the preceding forms of apparatus according tothe invention, the gas fed to Schmitt trigger 47 is clean initially, sothat a filter is not needed.

What has been described is a fluid amplifier cigarette inspection andrejection system that is very fast, being almost entirely withoutinertia, very reliable, being entirely or almost entirely Without movingparts or friction, and adaptable to a wide range of inspection ratesduring operation of a given machine. The bistable nature of theillustrated apparatus is very advantageous in that it divides cigarettesinto clearly acceptable and clearly rejected categories depending onlyupon what side of the arbitrary rejection line they fall, not how farabove or below that line they fall. This gives precision to thedivision, which is advantageous especially in those situations where theaccepted cigarettes must be guaranteed to meet a precise minimum fixedstandard. Where the division can be rougher, this attribute will weighless heavily.

The invention has been described with reference to a number of forms,but this was for illustration, not delineation. The illustrativeapparatus can be varied in numerous ways within the scope of theinvention. All embodiments, illustrated or not, that incorporate theprinciples of the invention are included within the claimed scopethereof.

What is claimed is:

1. Apparatus for inspecting cigarettes for leaks, comprising:

(a) gas pressure means for subjecting the interior of one of saidcigarettes to gas under a pressure different from the pressure outsidethe cigarette;

(b) monitoring means for monitoring the leakiness of said cigarette asrepresented by the gas pressure in the interior of said cigarette,comprising fluid amplifier means having a power stream, first and secondoutput channels, and a control input communicating with the gas pressurein the interior of said cigarette and effective to divert said powerstream from said first output channel to said second output channel onlywhen said gas pressure is outside a predetermined range;

(c) means responsive to a flow in said second output channel forrejecting said cigarette while it is being tested by said monitoringmeans;

(d) said gas pressure means including:

(1) conduit means communicating with said cigarette at both endsthereof; and

(2) a source of gas under pressure connected to said conduit means; and

(e) said control input communicates with the gas pressure in saidconduit means between said gas pressure source and the ends of saidcigarettes.

2. Apparatus for inspecting cigarettes for leaks, comprising:

(a) a testing station;

(b) motive means for moving cigarettes through said testing stationsequentially and in a predetermined spaced relation along a normalconveying path, said testing station extending along said path for nomore than one and one-half times said predetermined spaced relation;

(0) gas pressure means for subjecting the interior of a cigarettepassing through said testing station to gas under a pressure differentfrom the pressure outside the cigarette;

(d) monitoring means for monitoring the leakiness at any cigarettesubjected to said gas pressure means in said testing station asrepresented by the gas pressure in the interior of said cigarette,comprising bistable fiuid amplifier means having a power stream, firstand second output channels, and a control input communicating with thegas pressure in the interior of said cigarette and effective to switchsaid power stream from a stable state in said first output channel to astable state in said second output channel when said gas pressure isoutside of a predetermined range and thereby indicates a leak in thecigarette and;

(e) means responsive to output in said second output channel forejecting any said cigarette from said normal path before said cigaretteleaves said testing station.

3. Cigarette inspecting apparatus according to claim 2, furtherincluding means for resetting the output of said fluid amplifier meansfrom said second output channel to said first output channel when thecigarette following a leaky cigarette is not leaky.

4. Cigarette inspecting apparatus according to claim 2, furtherincluding synchronizing means allowing said power stream to be switchedto said second output channel only after the cigarette under test hasreached a predetermined point within said testing station, spaced fromthe end of the testing station by a distance smaller than the spacing ofthe cigarettes on said motive means, to ensure that the precedingcigarette has passed beyond the station before the power stream may beso switched.

5. Cigarette inspecting apparatus according to claim 2, wherein saidmeans responsive to output in said second output channel comprises, apassage leading to an orifice under any cigarette in said testingstation, said passage being connected to said second output channel.

6. Cigarette inspecting apparatus according to claim 2, wherein saidmeans responsive to output in said second output channel comprises, apassage leading to an orifice under any cigarette in said testingstation, a gas pressure source, and means including a normally closedpressure controlled valve connected between said source and saidpassage, said pressure controlled valve being responsive to the pressurein said second output channel.

7. Apparatus for inspecting cigarettes for leaks, comprising:-

(a) a testing station;

(b) motive means for supplying cigarettes sequential ly to and removingcigarettes sequentially from said testing station in a normal conveyingpath;

(c) gas pressure means for subjecting the interior of any said cigarettein said testing station to gas under a pressure different from thepressure outside the outside the cigarette in response to movement ofthat cigarette into said testing station;

(d) monitoring means for monitoring the leakiness of any cigarettesubjected to said gas pressure means in said testing station asrepresented by the air pressure in the interior of said cigarette,comprising a fluid trigger having a control input communicating with thegas pressure in the interior of said cigarette and eifective to switchthe output thereof from a normal channel to an alternate channel inresponse to and for as long as said gas pressure at said control inputis outside of a predetermined range and thereby indicates a leak in thecigarette, a fluid pulse generator adapted to generate a pulse each timean entering cigarette reaches a certain point within said testingstation, an output flip flop fluid amplifier having first and secondoutput channels and first and second control inputs, and sampling meansfor sampling said trigger alternate output channel each time said pulsegenerator produces a pulse and controlling said output flip flop toproduce output in said second output channel in response to coexistenceof said pulse and output in said alternate channel and until the nextsaid pulse; and

(e) means responsive to output in said output flip flop second outputchannel for ejecting any said cigarette in said testing station fromsaid normal path to a rejection path.

8. Cigarette inspecting apparatus according to claim 7, wherein saidsampling means comprises a control flip flop having the two outputchannels thereof connected respectively to said first and second outputflip flop control inputs, and a pair of NOR gates, one sampling saidtrigger normal output channel to constitute the rejection NOR gate, andthe other sampling said trigger alternate output channel to constitutethe restoring NOR gate, each said NOR gate sampling the output of saidfluid pulse generator, an alternate output channel of one NOR gate beingconnected to one control input of said control flip flop, and analternate output channel of the other NOR gate being connected to theother control input of said control flip flop.

9. Cigarette inspecting apparatus according to claim 7, wherein saidfluid pulse generator comprises a source of gas under pressure, aconduit supplied with gas from said source, a restriction in saidconduit, and means positively driven in synchronism with movement ofsaid motive means for venting said conduit at a point downstream fromsaid restriction each time said motive means moves so that any cigarettewithin said testing station reaches a predetermined point therein.

10. Apparatus for testing hollow articles for leaks, comprising:

(a) conveyor means for moving successive holllow articles in apredetermined spaced relation along a normal path through a testing zonehaving a length in the direction of movement no greater than one andone-half times the spacing between successive articles;

(b) means for connecting the interior of each article in the testingzone to a source of fluid under a pressure having a predetermineddifference from the ambient pressure outside said article;

(0) means for sensing the interior pressure of each article as it movesthrough the testing zone; and

(d) means for ejecting from said normal path each article whose interiorpressure is outside of a predetermined range of pressures and therebyindicates a leak in said article;

wherein the improvement comprises:

(e) first bistable fluid amplifier means operatively connected to saidejecting means and shiftable between a normal condition in which it doesnot actuate the ejecting means and a reject condition in which it doesactuate the ejecting means;

(f) second bistable fluid amplifier means in said sensing means toproduce a normal output signal only when the interior pressure of anarticle is within said predetermined range and a contrasting outputsignal when the interior pressure is outside said range;

(g) means synchronized with said conveyor means for producing a normaloutput signal except when an article passes a predetermined point insaid station, and a contrasting output signal only when an articlepasses said point; and

(h) third fluid amplifier means responsive only to concurrentcontrasting signals from both said signal producing means to switch saidfirst bistable fluid amplifier means to its reject condition.

11. Apparatus as defined in claim 10, including means responsive only toa contrasting signal from said synchronized means concurrently with anormal output signal from said second bistable fluid amplifier means toreset said bistable means to its normal condition.

12. Apparatus for testing cigarettes for leaks, comprising:

(a) conveyor means for moving successive cigarettes in a predeterminedspaced relation along a normal path through a testing zone having alength in the direction of movement no greater than one end onehalftimes the spacing between successive cigarettes;

(b) means for connecting the interior of each cigarette in the testingzone to a source of fluid under a pressure having a predetermineddifference from the ambient pressure outside said cigarette;

(c) means for sensing the interior pressure of each cigarette as itmoves through the testing zone;

(d) means selectively operable to eject cigarettes from said normal pathto a reject path;

(e) actuating means operatively connected to said ejecting means andshiftable between a normal condition in which it does not actuate theejecting means and a reject condition in which it actuates the ejectingmeans;

wherein the improvement comprises:

(f) fluid amplifier means in said sensing means including first andsecond output conduits, a power supply conduit, and a control inputconduit communicating with the interior of said cigarette;

(g) means responsive to the pressure in said control input conduit forcontrolling the division of flow from said power supply conduit betweensaid output conduits;

(h) means responsive to a predetermined flow in one of said actuatingmeans to its reject condition; and

(i) said operating means being located in said testing Zone andcooperating with said actuating means to eject a defective cigarettefrom the normal path before the cigarette leaves the testing zone.

References Cited LOUIS R. PRINCE, Primary Examiner.

I. NOLTON, Assistant Examiner.

US. Cl. X.R.

UNITED STATES PATENT OFFICE CER'IIFICATE OF CORRECTION Dated February11, 1969 Inventor(s)C0lin s. McArthur and Bruce wan McKnight and Col.

Col.

It is certified that error appears in the above-identified patent thatsaid Letters Patent are hereby corrected as shown below:

6, line 9, "inspecitm" should-read inspection 7, line 56, "values"should read .valves 9, line &2, "arm 10' should read arm 10 9, line 89,"comprise" should read compromise 11, line 71, -"imperiousness shouldread imperviousness 13, line 85, at the end of the line, "outside the"should be deleted.

1, line 2 4, the word "hollow" is misspelled;

1 line 71, "end" should read and 15, l1ne 22, after "said" insert outputconduits for operating said SIGNED AND QEALED mum mm! K. .38. Dominicanof Disclaimer 3,426,582.U0Zin Shaw IllaArthur and Bruce Wall McKnight,Winston-Salem, N .G. CIGARETTE INSPECTION APPARATUS. Patent dated Feb.11, 1969. Disclaimer filed July 19, 1972, by the assignee, R. J.Reynolds Tobacco Company. Hereby enters this disclaimer to claims 10and. 11 of said patent.

[Oficz'al Gazette Febma'ry 1.9, 1.974.]

